1. Field of the Invention
The present invention generally relates to a vehicle lamp. Specifically, the invention relates to a technology of effectively discharging heat in a vehicle lamp using a light emitting diode (hereinafter referred to as an “LED”) as a light source.
2. Related Art
Although an incandescent bulb, such as a halogen bulb or the like, a discharge bulb, or the like have been used as a light source in a vehicle lamps, according to the light source of the background art, the light source has a certain constant size requirement, which is accompanied by heat generation. Therefore, there is a limit in how small-sized the lamp can be formed.
Accordingly, there has been proposed a trial of downsizing a lamp by constituting a light source by a semiconductor light emitting element near to an ideal point light source and having a small heat generation amount.
In one case of a light source constituted by an LED, there is a trial of forming an LED unit for irradiating a desired pattern by one piece or an extremely small number of LEDs and a light control member for controlling light from the LED. There are several kinds of LED units for irradiating different patterns arranged at one lamp, and a beam of the desired pattern is irradiating by synthesizing the patterns irradiated from the plurality of LED units. This is possible because pattern design is comparatively easy because the LED is near to an ideal point light source.
However, when the one lamp is constituted by the above-described plurality of LED units, each of the LED units needs to be a small size. Therefore, even in the case of the LED having only a small heat generation amount in comparison with that of other light sources, such as an incandescent bulb or the like, when the LED is confined in a narrow space, the amount of heat accumulated in the space cannot be disregarded.
Patent Reference 1 shows that a plurality of lamp units each constituting a light source by LEDs (LED units) are supported by a common metal-made support member, and heat generated in accordance with lighting the LEDs is discharged by way of the metal-made support member.    [Patent Reference 1] JP-A-2004-311224
However, according to the vehicle lamp shown in Patent Reference 1, discharge of the heat of the LED is not sufficient.